This type of fastener system using a fastener ring associated with a blocking hoop is already known in the prior art. In general, the fastener ring includes reception means, e.g. a housing, making it possible to receive the dispenser member that can, for example, include a projecting collar for engaging by snap-fastening in the housing of the ring. In addition to the reception means, the fastener ring also includes a fastener skirt of substantially cylindrical shape defining an inside wall that is provided with one or more fastener profiles for coming into engagement with the neck of the reservoir. Conventionally, the neck of the reservoir forms a projecting annular outer reinforcement below which the fastener profile(s) are engaged in the final assembled position. The function of the blocking hoop is to prevent the inner profile(s) of the skirt of the ring from becoming disengaged from below the projecting outer reinforcement of the neck. In other words, the blocking hoop holds the fastener profile(s) of the ring captive against the neck of the reservoir. To enable the profile(s) to pass beyond and below the projecting annular reinforcement of the neck, it is possible to make the skirt of the ring with longitudinal slots so as to divide the skirt into a plurality of tabs that are separated by slots. In a variant, it is possible to leave the skirt continuous, and to take advantage of the elasticity and the deformability of the skirt in order to enable the fastener profile(s) to pass over the projecting annular reinforcement of the neck. Either way, it is necessary for the skirt of the ring to be able to deform radially outwards while passing over the reinforcement of the neck. The function of the blocking hoop is to prevent the skirt of the ring from deforming radially outwards once the fastener profile(s) is/are engaged below the reinforcement of the neck.
In general, the final assembled position in which the blocking hoop prevents the ring for becoming disengaged from the neck is a permanent position, in the sense that it is no longer possible to remove the blocking hoop from the ring so as to enable the ring to be removed from the neck. Consequently, in order to remove a dispenser unit using such a fastener system, it is necessary to destroy the hoop, the ring, or the neck. The hoop is held on strongly, such that its resistance to traction cannot be overcome by axially pulling on the hoop, without damaging or destroying it.
However, in some circumstances, it can turn out to be useful to disassemble the dispenser, i.e. to remove the dispenser unit from the reservoir. When the reservoir is for refilling once it has been emptied, a screw-fastener system is generally used. The ring and blocking-hoop fastener system turns out to be not very suitable, given that the hoop is put into place on the ring in permanent manner. Disassembly can also turn out to be useful in order to recycle the dispenser by separating the various component materials. In theory, this is possible with the ring and blocking-hoop fastener system, but that requires one of the ring, the hoop, or the neck to be destroyed, which operation is random and therefore difficult to industrialize.